ISA Certified Control Systems Technician (CCST) program
Certified Control System Technicians (CCSTs) calibrate, document, troubleshoot, and repair/replace instrumentation for systems that measure and control level, temperature, pressure, flow, and other process variables.
This question comes from the Level I study guide, Domain 3, Troubleshooting. Level I represents a professional who has a five-year total of education, training, and/or experience.
The line symbol from ISA-5.1-1984 (revised 1992)
A. Mechanical link
B. Electrical signal
C. Pneumatic signal
D. Hydraulic signal
The correct answer is C, a pneumatic signal.
Here are the symbols for answers A, B, C, and D.